How to improve reflection pass

[Oleg_Budeanu]

Just wondering, i am rendering 6k still image now and i have this issue. All the passes (Specular, GI, Lighting), except reflection pass, are clean. So what is the best way to improve reflection pass only? In older days we'd rise subdivs for materials responsible for reflection noise, though now we are using the adaptive method.
Here are screenshots of passes:
Samplerate : https://dl.dropboxusercontent.com/s/...523_143422.png
GI (irradiance map) : https://dl.dropboxusercontent.com/s/...523_143446.png
Lighting : https://dl.dropboxusercontent.com/s/...523_143515.png
Reflection : https://dl.dropboxusercontent.com/s/...523_143536.png
Specular : https://dl.dropboxusercontent.com/s/...523_143552.png
RawLighting : https://dl.dropboxusercontent.com/s/...523_143626.png
Noise level pass : https://dl.dropboxusercontent.com/s/...523_143643.png
Settings are quite straightforward with 35 shading rate and AA 1-6 and noise threshold 0.005

[joconnell]

Up shade rate more, lower noise thresh!

[Oleg_Budeanu]

Think is that I am happy with samplerate, except the reflective areas, where AA kicks in. I increased shade rate till 45 and used a couple of local multipliers per object. Much better. Though I am quite surprised that I should go that high with shading rate! I expected that it will be fine on 20-25.

[joconnell]

I'd say having your aa at 1-6 might give you a lower number reflection samples since you're working off shading rate. It might not be a huge amount in the context of how complex your lighting or materials are, especially if there's some small details!

[Oleg_Budeanu]

I'd say having your aa at 1-6 might give you a lower number reflection samples since you're working off shading rate. It might not be a huge amount in the context of how complex your lighting or materials are, especially if there's some small details!

I see. Well to be honest there is nothing that complex, as this is day to day work - no layered materials and etc. Though good to know that this is not something odd. Thanks !

[vlado]

I would generally advise increasing the min. subdivs for the image sampler rather than increasing the shading rate. This allows V-Ray to be more flexible with the sampling if a higher number of samples are needed.

Best regards,
Vlado

[Oleg_Budeanu]

I would generally advise increasing the min. subdivs for the image sampler rather than increasing the shading rate. This allows V-Ray to be more flexible with the sampling if a higher number of samples are needed.

Best regards,
Vlado

You mean raising AA from 1-6 to something like 2-6 or 4-6?
But that will affect whole render even where AA is fine for me, or i got something wrong?

[kosso_olli]

1-6 seems very low. In general the new defaults of Vray are giving very good results compared to the render time. I rarely change them anymore...